Objective, Subjective and Intersubjective Selectors
of Knowledge

ABSTRACT. It is argued that the acceptance of knowledge in a
community depends on several, approximately independent selection "criteria".
The objective criteria are distinctiveness, invariance and controllability,
the subjective ones are individual utility, coherence, simplicity and novelty,
and the intersubjective ones are publicity, expressivity, formality, collective
utility, conformity and authority. Science demarcates itself from other
forms of knowledge by explicitly controlling for the objective criteria.

Introduction

It is with great pleasure that I use this opportunity to comment on
Donald T. Campbell's last paper (1997). I came into contact with Don's
work at the beginning of my research career, in 1984, during a conference
on evolutionary epistemology at the University of Ghent. Since then, his
writings have been a constant source of inspiration. After we met, in 1990,
we started to regularly exchange publications. Each time I received a bunch
of his papers, I began reading them with much pleasure, because I knew
that I would find every paragraph teeming with deep insights and surprising
observations. We finally decided to collaborate, producing an ambitious
review paper about the evolution of social systems (Heylighen & Campbell,
1995). We were planning to write more papers together, but that has been
made impossible by his untimely death in 1996. I see the present paper
as an opportunity to somehow continue my collaboration with Don, adding
my insights to his in a collective publication.

As may have become obvious, there is virtually no disagreement between
my philosophical position and the one of Donald Campbell. The differences
in approach have more to do with theoretical background and methods than
with aims or convictions. While Campbell (1974) called his philosophy of
knowledge "evolutionary epistemology", I would characterize mine
as "evolutionary-cybernetic epistemology" (Heylighen,
1993). "Cybernetic" refers here to the broad domain of cybernetics
and general systems theory (Ashby, 1956; von Bertalanffy, 1968), and its
transdisciplinary study of organization, communication, control and modelling.
This epistemology is part of the larger evolutionary-cybernetic philosophy
which, together with others, I am trying to develop in the Principia Cybernetica
Project (Joslyn, Heylighen and Turchin, 1993; http://cleamc11.vub.ac.be/).
Compared with a purely evolutionary approach, a cybernetic epistemology
puts more emphasis on the structure of cognitive systems, on the processes
by which they are constructed, on the control they provide over the environment,
and on the communication of knowledge. Such a cybernetic analysis, for
example, allows the reinterpretation of Campbell's (1974) "nested
hierarchy of vicarious selectors" as the result of a series of metasystem
transitions, producing subsequent control levels (Heylighen, 1995).

The ideas of cybernetics inspired much of Campbell's work, as illustrated
by his recurring references to the work of Ashby, his long time support
for the perceptual control approach of Powers (1973), and his enthusiastic
endorsement of the Principia Cybernetica Project. However, I guess it was
a lack of expertise in the mathematical and computational models of cybernetics
which kept him from using the "cybernetics" label more explicitly.

Different co-selectors of knowledge

A large part of Campbell's (1997) paper, which provides the focus of
this memorial issue, is devoted to a discussion of the different selectors
which together determine the evolution of knowledge. The main thrust is
that the referent, i.e. the external object which the knowledge
is supposed to represent, only plays a relatively small part in the selection
of a particular idea or belief. In spite of its ideology, scientific knowledge
too is the product of multifarious selective forces, most of which have
little to do with objective representation of the referent. Of the other
co-selectors, Campbell pays special attention to the vehicle through which
the knowledge is expressed and to the need to maintain the community which
carries the knowledge. In addition to these primarily social selectors,
he discusses the selectors of interests and historicity, which function
on the individual level.

Whereas Campbell analyses these selectors structurally, that
is, by the specific object or component responsible for the selection,
I will here try to classify them functionally, that is, by the role
they play in the evolution of knowledge. The class of selectors that promote
the same type of characteristics can be said to determine a selection
criterion. Implicit in Campbell's examples, we can find three superclasses:
objective criteria (selection for fit to the outside object), subjective
criteria (selection for assimilation by the individual subject) and intersubjective
criteria (selection for sharing between subjects). These superclasses can
be divided into more fine-grained subclasses. The resulting classification
will allow us to highlight the differences between scientifically derived
knowledge, which supposedly privileges the objective criteria, and other
types of knowledge and belief, where subjective and intersubjective factors
play a larger role.

However, as Campbell emphasizes, it is impossible to really separate
the different selectors. All the different types of selectors will affect
the evolution of knowledge, scientific or other. Therefore, the overall
probability for a belief to be selected will be a kind of weighted sum
of the degrees to which it fulfils each of the criteria. For example, an
idea that scores high on the objective criteria and low on the subjective
ones, is less likely to survive selection than an idea that scores high
on both counts. In this view, no single criterion can guarantee selection,
or provide justification for a belief. We can only use the simple heuristic
that the more criteria an idea satisfies, and the higher the degree of
satisfaction, the "fitter" it is, and the more likely to win
the competition with rival beliefs (Heylighen, 1993).

In such a view, there is in general no single "best" idea.
An idea may score high on certain criteria, while another idea scores high
on other criteria. Such ideas are in general incomparable. The one is likely
to win the competition in certain contexts, but to lose in others. This
is similar to the natural selection of organisms: sharks are not more or
less fit than seaweed or than shrimps. Each species is adapted to its particular
niche within the larger shared environment. However, within the shark niche,
some shark designs will be fitter than others. In both organisms and beliefs,
"being fitter than" is a partial order, not an absolute
one (Heylighen, 1997). Such a philosophy synthezises the relativism of
philosophers who emphasize the "incommensurability" of theories,
with the more traditional belief in the objectivity of scientific progress.

Objective Selection Criteria

Since, as Campbell (1997) reminds us, we have no direct access to the
"Ding an Sich", we can only use indirect means to determine whether
a belief corresponds to an objective reality. Like the constructivist cyberneticians
von Foerster (1981), and Maturana & Varela (1987) note, in the nervous
system there is no fundamental distinction between a perception and a hallucination:
both are merely patterns of neural activation. However, subjectively most
people have no difficulty distinguishing dreams or fantasies from perceptions.

To find out whether a perception is real, you should determine whether
it is caused by an external referent, or by an internal mechanism (e.g.
imagination, or malfunctioning of the perceptual apparatus). According
to attribution theory (Kelley, 1967), people attribute causes of perceived
effects to those phenomena that covary with the effects. External
phenomena will covary with their external causes, but not with changes
that only affect internal, subjective variables. This leads to the following
criteria for judging objectivity or "reality":

1. Invariance: phenomena should not disappear when the way of
perception is changed. The larger the domain over which it remains invariant,
the more "real" it will be (cf. Bonsack, 1977). Kelley (1967)
proposes the following more specific types of invariance:

a. invariance over modalities: if the same phenomenon is perceived
through different senses (e.g. sight and touch), points of view, or means
of observation, it is more likely to objectively exist.

b. invariance over time: a perception that appears or disappears
suddenly is unlikely to be caused by a stable referent.

c. invariance over persons: a perception on which different
observers agree is more likely to be real than one that is only perceived
by a single individual.

2. Distinctiveness: different referents produce different perceptions
(Kelley, 1967; cf. Campbell, 1992). A perception that remains the same
when the attention is directed elsewhere is likely to be produced by the
perceptual system itself (e.g. a particle of dust in the eye). Moreover,
"real" perceptions tend to be characterized by richness in contrast
and detail (imagined or dream perceptions typically are coarse-grained
and fuzzy) and to exhibit "Gestalt qualities", such as regularity,
closure and simplicity, thus proposing a distinct, coherent pattern, rather
than an unstructured collection of impressions (Stadler & Kruse, 1990).
Campbell (1966, 1997) too notes that detailed pattern increases the plausibility
of percepts.

Extending this logic of covariation, I would like to add the criterion
of controllability: a phenomenon that reacts differentially to the
different actions performed on it, is more likely to be real than one that
changes randomly or not at all. This criterion underlies the method of
preparation-detection, which characterizes scientific experimentation.
Controllability, however, is to some degree dependent on the observing
subject: although I am not able to influence the trajectory of a far-away
plane, its pilot is. This leads us to the subjective criteria.

Subjective selection criteria

For beliefs to be accepted and retained by an individual, it is not
sufficient that they correspond to distinct, invariant and controllable
phenomena. A relativistic quantum field model of the beryllium atom may
fulfil all objective criteria to be valid knowledge, yet very few people
would ever assimilate, remember or pass on such knowledge. Therefore, from
a selectionist point of view, the model is rather unsuccessful.

Most obvious among the subjective selection criteria is individual
utility. People will only do the effort to learn and retain an idea
that can help them to reach their goals. From a long-term evolutionary
perspective, such goals and values derive from inclusive fitness. Organisms
that assimilate knowledge which increases their fitness are more likely
to survive and pass on that knowledge to their offspring. Assimilating
useless knowledge, on the other hand, only burdens the subject.

Indeed, the capacity of a cognitive system is limited. Therefore, knowledge
should be easy to learn. The most straightforward determinant of learning
ease is simplicity: the more complex an idea (i.e. the more components
and more connections between components it has, see Heylighen, 1997), the
higher the burden on the cognitive system. Simplicity is listed as a subjective
criterion, because it is relative to the concepts and associations which
the subject already knows. For example, the model of a beryllium atom may
seem simple for a physicist well-versed in atomic models, but hopelessly
complex for a layman.

More generally, the ease with which a cognitive system assimilates new
ideas depends on the support they get from ideas assimilated earlier (this
is an example of Campbell's (1997) "historicity"). This requirement
for ideas to "fit in" the existing cognitive system may be called
coherence (Thagard, 1989). Coherence encompasses connection and
consistency. Since learning is based on strengthening associations, ideas
that do not connect to existing knowledge simply cannot be assimilated.
The preference for consistency follows from the fact that a fit individual
must be able to make clear-cut decisions. Mutually contradictory rules
("cognitive dissonance") will create a situation of confusion
or hesitation, which is likely to diminish the chances for survival.

Complementary to the conservatism promoted by the coherence criterion
is the criterion of novelty. New, unusual or unexpected ideas or
perceptions tend to attract the attention, and thus arouse the cognitive
energy which will facilitate their assimilation. This is another adaptation,
which helps organisms to cope with unusual situations. It shows itself
in the exploratory behavior of animals. The corresponding human emotion
is curiosity.

Intersubjective selection criteria

Most of the beliefs a subject has were not individually constructed,
but taken over from others. This process of diffusion plays an essential
part in the selection of ideas. Only ideas that are transmitted frequently
are likely to be assimilated frequently. Each time an idea is communicated,
it replicates, i.e. is copied into another cognitive system. Thus, ideas
can be modelled as replicators similar to genes: memes (cf. Heylighen,
1992). The conversion of an individual to a new belief is in a way similar
to an infection, i.e. the passing on of a "cognitive virus".

The first criterion which will determine how often an idea is transmitted
is the amount of propaganda or publicity, that is, the effort the
subject carrying the idea invests in making it known to others. That motivation
largely depends on the other criteria: you will be more inclined to spread
an idea if it is simple, useful, novel, etc. However, some beliefs include
their own motivation. This is most visible in religions, cults, fashions
and ideologies, which often include explicit rules that believers should
go and spread the word. This may be explained by "selfish meme"
selection (Heylighen, 1992): selection at the level of the meme, which
benefits the spread of the idea, but which is useless or even dangerous
for the individual carrying the idea. Such ideas can be compared to cognitive
parasites, which "hitch a ride" on a cognitive system without
caring for the well-being of that system.

All memes, "selfish" or not, need a communication medium
in order to be transmitted. Ideas that are easy to express in a particular
language or medium will be propagated more easily. This is the criterion
of expressivity. It depends on the medium: some ideas are easier
to formulate in one language than in another. Thus, like Campbell (1997)
notes, the medium will co-select the idea. For example, it is difficult
to imagine the evolution of physical theories without the mathematical
language in which they are formulated.

The expression of an idea in an intersubjective code or language does
not yet guarantee its accurate transmission. All expressions are to some
degree indexical: their meaning depends on the context. Different people
are likely to interpret them differently, thus assimilating an idea different
from the one that was expressed. However, some expressions are formulated
in less context-dependent way. The resulting lack of equivocation may be
called formality. The more formally an idea is expressed, the better
it will survive repeated transmissions. For example, ideas are more likely
to be communicated accurately through logic and mathematics than through
poetry or painting.

The group equivalent of usefulness may be called collective utility.
Some forms of knowledge benefit the collective, while being useless for
an isolated individual. Languages, traffic regulations, technical standards
and moral codes are examples of cognitive entities that have value only
for intersubjective purposes. Such collective ideas will be selected at
the group level: groups having such beliefs will be more fit than groups
lacking them. This how the supernatural cosmologies characterizing archaic
civilisations discussed by Campbell (1997) have been selected.

However, as Campbell emphasizes, such group selection often runs counter
to the more powerful and direct force of individual selection. Therefore,
he proposes a mechanism that suppresses individually selfish deviations
from these collective beliefs: conformist transmission. As illustrated
by the mathematical model of Boyd and Richerson (1985), all other things
being equal, it seems evolutionarily optimal for subjects to adopt the
majority or plurality belief rather than a minority idea. Thus, already
popular ideas tend to become even more popular, leading to an eventual
homogeneity of belief within a closely interacting group. This selective
pressure may be called conformity.

Complementary to this homogenizing influence, we find the diversifying
effect of the division of labor. Because of their limited cognitive capacity,
individuals within a complex society tend to specialize in a particular
domain. As illustrated by Gaines's (1994) computer simulation, this process
of cognitive differentiation is driven by a positive feedback mechanism:
individuals who were successful in solving a particular type of problem
will get more of these problems delegated to them, and thus develop a growing
expertise or authority in that domain. The backing of a recognized expert
will contribute to the acceptance of a particular idea. This is the criterion
of authority.

The integration on the level of norms and codes fostered by conformity
and the differentiation on the level of expertise fostered by authority
together produce a complexification (cf. Heylighen, 1997) of the social
system. The process is similar to the metasystem transition which produced
the differentiated organs and tissues in a multicellular organism (Heylighen
& Campbell, 1995; Heylighen, 1995).

Objective Criteria

Invariance

Distinctiveness

Controllability

Subjective Criteria

Individual Utility

Simplicity

Coherence

Novelty

Intersubjective Criteria

Publicity

Expressivity

Formality

Collective Utility

Conformity

Authority

Table 1: summary of the proposed selection criteria

Scientific Validity and the Demarcation Problem

The selection criteria we discussed are summarized in table 1. When
we look at the evolution of scientific knowledge, it is clear that all
these criteria play a role in the selection of ideas. The objective criteria
obviously underlie the experimental method: new concepts are operationalized
by specifying the observations that will distinguish their referents, by
subjecting them to controlled experiments, and by trying to find results
which are maximally independent of place, time, observer or means of observation
(as Campbell (1997) notes, the latter is often difficult in the social
sciences). Moreover, subjective interpretation is minimized by formalization
of the theories and concepts. However, from otherwise equivalent ideas,
scientists will still tend to prefer those that may bring fame and fortune,
that are simple, coherent with what they already know, and novel. In addition,
the social system of science will prefer ideas that have vocal advocates,
are strikingly expressed, benefit the community, and are supported by the
majority, or by authoritative experts.

In what way, then, can science be demarcated from other knowledge producing
systems, such as religion, fashion or tradition? The difference is that
science explicitly promotes the objective criteria. (To a smaller
degree, as Campbell (1997) notes, science also tries to neutralize the
criteria that are likely to detract from objectivity, such as authority
which is not backed by expertise, conformity for conformity's sake, and--at
least in the pure sciences--utility.) The objective criteria have been
built into the scientific method. They have become part of knowledge itself,
rather than an outside force to which knowledge is subjected. The scientific
method, in Campbell's (1974) terminology, is a vicarious selector, an interiorization
of external selectors.

This vicarious selector functions at a higher hierarchical level than
the knowledge it produces. Because other forms of knowledge are not selected
at this higher level, they will evolve in a less efficient way, and are
therefore likely to be of lower quality. The difference between scientific
and other knowledge is not an absolute one, between objective and subjective,
or between justified and unjustified, but one of degree, between the products
of a systematic process of improvement, and those of a slow, haphazard
process of trial-and-error, where neither trial nor error are consciously
controlled.

Acknowledgment:

During this research the author was supported as a Senior Research Associate
by the FWO (Fund for Scientific Research, Flanders).